Bis-(hindered phenol)-alkane phosphonates

ABSTRACT

Bis-(hindered phenol)-alkane phosphonates having the formula   WHEREIN R is alkyl or other groups can be prepared by condensation reactions. These compounds are useful as stabilizers of organic materials subject to oxidative deterioration.

United States Patent Spivack et al.

[ July 11, 1972 [54] BIS-(HINDERED PHENOL)-ALKANE PHOSPHONATES [72]inventors: John D. Spivack, Spring Valley Martin Dexter, BriarcliffManor, both of NY.

[73] Assignee: Ciba-Geigy Corporation, Ardsley, NY.

[22] Filed: May 19, 1969 [2i] Appl. No.: 825,918

OTHER PUBLICATIONS lliopulos et al., Chemical Abstracts, Vol. 63 (1965)page 9,979 and 9.980

Primary Examiner-Joseph Rebold Assistant Examiner-Richard L. RaymondAttorney-Karl F. .lorda, Bruce M. Collins, Martin J. Spellman, Jr. andNestor W. Shust [57] ABSTRACT Bis-(hindered phenol)-alkane phosphonateshaving the formula wherein R is alkyl or other groups can be prepared bycondensation reactions. These compounds are useful as stabilizers oforganic materials subject to oxidative deterioration.

7 Claims, No Drawings DETAILED DESCRIPTION This invention relates tobis-(hindered phenol )-alkane phosphonate compounds and compositionsotherwise subject to oxidative deterioration stabilized by theincorporation therein of said compounds.

In particular the present invention pertains to bis-(hinderedphenol)-alkane phosphonates having the formula:

wherein R, R, R and R are hydrogen alkyl groups having one to l8 carbonatoms or cycloalkyl having five to 12 carbon atoms,

R is hydrogen or alkyl having up to 18 carbon atoms,

R is alkyl, alkaryl or aralkyl having up to 30 carbon atoms or alkylthio(lower alkyl where the alkyl has up to 30 and (lower) alkyl up to sixcarbon atoms,

G is alkylene group having from one to six carbon atoms,

m is or I.

By the term alkyl and alkylene", is intended groups containing branchedor straight chains. Representative alkyl groups are methyl, ethyl,propyl, isopropyl, butyl, t-butyl, octyl, t-octyl, decyl, dodecyl,octadecyl, tetracosyl, triacontyl and the like. Representative alkylenegroups are methylene, ethylene, propylene, isopropylene, butylene,t-butylene, hexylene and the like. Cycloalkyl groups are illustrated bycyclopentyl, cyclohexyl, cyclooctyl, cyclodecyl, cyclododecyl and thelike. Illustrative examples of alkyl thio (lower) alkyl group aremethylthioethyl, hexylthiomethyl, decylthioethyl, dodecylthiobutyl,hexadecylthiohexyl, tetradecylthioethyl, triacontylthioethyl and thelike. Aralkyl are illustrated by benzyl, phenylethyl, o-phenylhexyl,l2-phenyldodecyl, 12-mnapthyldodecyl, 24-phenyltetracosyl,30-phenyltriacontyl and the like.

In the above formula the phenolic group has two alkyl substitutents. Onealkyl substituent is in a position ortho to the hydroxy group and asecond alkyl group is either (a) in the other position ortho to thehydroxy group or (b) in the position meta to the hydroxy group and parato the first alkyl group. Preferred are the dialkyl-4-hydroxyphenylgroups wherein the alkyl groups are branched groups such as t-butyl ort-octyl. However, other arrangements are also contemplated, such as3t-butyl-6-methyl-4-hydroxyphenyl group,3,5-di-isopropyl-4-hydroxyphenyl group, 3,5-di-t-octyl-4- hydroxyphenylgroup, 3,5-dimethyl-4-hydroxyphenyl group or3,5-di-n-octadecyl-4-hydroxyphenyl group.-

In a preferred embodiment, R, R, R and R are lower alkyl groups havingup to eight carbon atoms, especially tertiary alkyl groups such astert-butyl, tert-amyl, tert-octyl and the like. Group G is preferablymethylene and m can be zero or one. R is preferably an alkyl grouphaving four to 24 carbon atoms and most preferably eight to 24 carbonatoms when the integer m is zero. However, when the integer m is one, Ris an alkyl group having from one to 24 carbon atoms. R groups are alkylor alkaryl groups having up to 30 carbon atoms.

The bis-( hindered phenol)-alkane phosphonates of this invention can beprepared by a variety of condensation procedures. One method is tocondense a haloalkyl ketone with a phenol or a hindered phenol in thepresence of a Lewis EXAMPLE 1 Preparation of diethyl2,2-bis-(3,5'-di-t-butyl-4'-hydroxyphenyl)-1-propane phosphonate A.2,2-Bis-( 3 ,5 '-di-t-butyl-4 '-hydroxyphenyl l chloropropane To asolution containing 46.] parts of chloroacetone, 206 parts of 2,6di-t-butylphenol and 200 parts by volume of ethylene chloride, was added98 parts of sulfuric acid. The reaction mixture was stirred for 2 hoursat 1 5 to -10 C. and poured into a cooling mixture of 300 parts of iceand 300 parts of water. The resulting dispersion was diluted with 3liters of ethanol and allowed to stand overnight. The precipitate wasfiltered, dried, triturated in hexane and the resulting solidrecrystallized from n-hexane yielding the product melting at l5lto 153C.

Elemental Analysis:

Calculated: C76.4 I; H9.72, Cl7.28 Found: C76.l5; H9.l6; Cl-7.20

B. Diethyl 2,2Bis-(3 ',5'-di-t-butyl-4'-hydroxyphenyl lpropanephosphonate To 2.76 parts of diethyl phosphite dissolved in 100parts by volume of xylene was added 0.46 parts sodium. The reactionmixture was heated at C. until all of sodium was reacted. The product ofpart (A) above was then dissolved in 25 parts by volume of xylene andadded slowly at 45 to 50 C. to the reaction mixture. The resultingreaction mixture was heated at 50 C. for 3 hours and then evaporated todryness under a reduced pressure. The residue was dissolved in 50 partsby volume of methanol, water was added to the methanol solution to thepoint of turbidity and the solution was then filtered. The filtrate wasconcentrated to dryness and the residue was recrystallized from heptaneyielding the product melting at l56to 158C.

Elemental Analysis:

Calculated: C-7 1 .36; I-I9.76; P5.26 Found: 6-70.83; H9.60; P5.24

EXAMPLE 2 Dimethyl 2,2-bis(3 ,5 '-di-tert-butyl-4 -hydroxyphenyl lnonadecanephosphonate lf 159 parts of l-chlorononadecanone-2 is reactedaccording to step (A) of Example 1 to yield2,2-bis(3',5'-di-tertbutyl-4-hydroxyphenyl)-l-chlorononadecane which inturn is reacted with 2.2 parts of dimethyl phosphite is reactedsubstantially as in step (B), the resulting product will be dimethyl2,2-bis( 3 ,5 '-di-tert-butyl-4'-hydroxyphenyl )-lnonadecanephosphonate.

EXAMPLE 3 Preparation of dimethyl a,a-bis-(3,5-di-isopropyl-4-hydroxyphenyl)-noctadecylphosphonate To thereaction vessel flushed with nitrogen were added 15 g of dimethyloctadecanoylphosphonate and 28.4 g of 2,6- diisopropylphenol. Theingredients were melted and then cooled to 3540 C. and saturated withboron trifluoride. Cooling was required to maintain the temperaturebelow 40 C. The reaction mixture was stirred for 40 min. at 50-55 C.,and then dissolved in 40 ml. of acetic acid and the solution poured oncrushed ice. The resulting mixture was extracted with benzene and theextract washed successively with 6 N hydrochloric acid and water andthen dried over anhydrous sodium sulfate. The solvent was distilled offat C. and 0.4 mim of pressure, yielding 29 g of a residue. The residuewas dissolved in ml. of boiling acetonitrile and on cooling the solutiona solid was obtained which was ground and triturated with acetonitrile.The resulting slurry was cooled, filtered and washed with acetonitrileyielding 24.5 g. of the product. Upon recrystallization of the productfrom hot petroleum ether an analytical sample was obtained which had themelting point of 70-72 C. and analyzed as follows:

%C HI 1:?

Calculated: 73.90 10.58 4.33 Found: 74.24 10.10 4.33 74.16 10.25 4.29

EXAMPLE4 Preparation of dimethyl-a,a-bis-( 3-methyl-4-hydroxyphenyl)-n-octadecylphosphonate Following the procedure described in Example 3,22.5 g of dimethyl octadecanoylphosphonate was reacted with 25.9 g. ofo-cresol to yield dimethyl-a -bis-(3-methyl-4-hydroxyphenyl)octadecylphosphonate. The product was a white crystalline solidmelting at 159-1 61 C. after recrystallization from ethyl acetate.

EXAMPLE 5 Preparation of dimethyl-apt -bis-(4-hydroxyphenyl)-noctadecyl-phosphonate Following the procedure described in Example 3,26.3 g. of dimethyl octadecanoylphosphonate was reacted with 26.4 g. ofphenol yielding dimethyl-(1,11-bis-(4-hydroxy-phenyl)-n-octadecylphosphonate in the form of whitecrystals having a melting point of l69-l72 C. after successiverecrystallization from isopropanol and ethyl acetate.

Elemental Analysis:

Calculated: C70.29', H9.42; P5.66 Found: C-70.58; H-9.2l; P5.7l

EXAMPLE 6 EXAMPLE 7 Preparation of diphenyl-a,a-bis-(3,5-diisopropyl-4-hydroxyphenyl)nonanephosphonate Following theprocedure of Example 3, 2,6-diisopropylphenol is reacted withdiphenyl-n-nonanoyl phosphonate to yield the product.

EXAMPLE 8 Preparation of di-p-t-octylphenyl-2,2-bis-(3,5'-di-t-butyl-4'-hydroxyphenyl)-l-hexanephosphonate Following the procedure of Example 1,in step (A) 2,6-di-tbutyl-4-hydroxyphenol is reacted withl-chlorohexanone-2 to yield the intermediate2,2-bis-(3',5'-di-t-butyl-4'-hydroxyphenyl)-l -chlorohexane. In step (B)said intermediate is reacted with di-p-t-octylphenylphosphite to yieldthe product.

EXAMPLE 9 Preparation of ditriacontyl-5,5-bis-(3 ',5'-di-t-butyl-4'-hydroxyphenyl)-n-hexanephosphonate.

Using the procedure of Example 1, in step (A) 6-bromo-nhexanone-2 isreacted with 2,6-di-t-butylphenol to yield 2,2- bis-( 3,5'-di-t-butyl-4'-hydroxyphenyl)-6-bromohexane as the intermediate. Saidintermediate is reacted in step (B) with bis- (triacontyl)phosphite toyieldditriacontyl-5,5-bis-(3',5'-di-tbutyl-4-hydroxyphenyl)-n-hexanephosphonate.

EXAMPLE 10 Preparation of didodecylbenzyl-a,a-bis-(3,5-di-isopropyl-4-hydroxyphcnyl n-octadecylphosphonate.

Following the procedure described in Example 3, didodecylbenzyloctadecanoylphosphonate is reacted with 2,6-diisopropylphenol to yieldthe product.

The bis-(hindered phenol)-alkylene phosphonates of the present inventionare stabilizers of organic materials normally subject to oxidativedeterioration. Materials which are thus stabilized according to thepresent invention include synthetic organic polymeric substances such asvinyl resins formed from the polymerization of vinyl halides or from thecopolymerization of vinyl halides with unsaturated polymerizablecompounds, e.g., vinyl esters, a,B-unsaturated aldehydes and unsaturatedhydrocarbons such as butadienes and styrene; polya-olefins such aspolyethylene, polypropylene, polybutylene, polyisoprene and the like,including copolymers of poly-aolefins; polyurethanes such as areprepared from polyols and organic polyisocyanates; polyamides such aspolyhexamethylene adipamide and polycaprolactam; polyesters such aspolymethylene terephthalates; polycarbonates; polyacetals; polystyrene;polyethyleneoxide; and copolymers such as those of high impactpolystyrene containing copolymers of butadiene and styrene and thoseformed by the copolymerization of acrylonitrile, butadiene and/orstyrene. Other materials stabilized according to the present inventioninclude lubricating oil of the aliphatic ester type, e.g.,di-(2-ethylhexyl)-azelate, pentaerylthritol tetraceproate and the like;animal and vegetable derived oils, e.g., linseed oil, fat, tallow, lard,peanut oil, cod liver oil, castor oil, palm oil, corn oil, cotton seedoil and the like; hydrocarbon material such as gasoline, both naturaland synthetic diesel oil, mineral oil, fuel oil, drying oil, cuttingfluids, waxes, resins and the like, fatty acids such as soaps andthelike.

In general the stabilizers of this invention are employed from about0.005 percent to about 10 percent by weight of the stabilizedcomposition. A particularly advantageous range for polyolefins such aspolypropylene is from about 0.01 percent to about 5 percent.

The stabilizers employed in this invention may be used alone or incombination with other stabilizers or additive materials. Especiallyuseful in certain cases is a composition containing an active compoundof the present invention with the stabilizer dilauryl B-thiodipropionateor distearyl [3- thiodipropionate.

Furthermore, compounds of the formula:

wherein R is an alkyl group having from six to 24 carbon atoms; and

n is an integer from I to 6, are useful stabilizers in combination withthe novel antioxidant compounds of the present invention.

Other antioxidants, antiozonants, thermal stabilizers, ultraviolet lightabsorbers, coloring materials, dyes, pigments, metal chelating agents,etc., and light stabilizers may also be used, in combination, with theactive compounds of the present invention.

OVEN AGING TEST Unstabilized polypropylene powder (Hercules Profax 6501is thoroughly blended with an antioxidant. The blended material is thenmilled on a two roller mill at 182 C. for 10 minutes after which timethe stabilized polypropylene is sheeted from the mill and allowed tocool.

The milled polypropylene sheet is then cut into small pieces and pressedfor 7 minutes on a hydraulic press at 218 C. and 2,000 pounds per squareinch pressure. The resultant sheet of 25 mil thickness is cut into smallplaques and tested for resistance to accelerated aging in a forced draftoven at C.

When unstabilized polypropylene is tested as described above, its ovenlife is about 3 hours.

FADEOMETER TEST The 25 mil plaques prepared as described in the OvenAging Test are placed on a white card stock background and exposed in aFadeometer. The specimens are tested for embrittlement at 20 hoursintervals by bending them 180. The result of this test is recorded asthe number of hours the specimen stayed in the Fadeometer until a cleanbreak is obtained.

Unstabilized polypropylene tested in a Fadeometer as noted above willgenerally fail after 40 to 60 hours.

The following examples are intended to illustrate further the nature ofthe present invention without introducing any limitations.

EXAMPLE Using the procedure described above, polypropylene wasstabilized with 0.5 percent by weight of diethyll,2-bis(3,5-dit-butyl-4-hydroxyphenyl)-ethanephosphonate. The thusstabilized polypropylene had the oven aging life of 120 hours.

Comparable stabilization is obtained when said stabilizer is employed inthe amount of 0.01 percent by weight of polypropylene.

This Example was repeated except that said stabilizer was employed inthe amount of 0.1 percent by weight in combination with 0.5 percent byweight of dilaurylthiodipropionate. Upon testing the following resultswere obtained:

275 hrs. 240 hrs.

Oven Aging Test Fadeometer Test EXAMPLE ll rylthiodipropionate thefollowing results were obtained:

Oven Aging Test 537 hrs. Fadeometer Test 420 hrs.

EXAMPLE l2 Polypropylene was stabilized as described above with 0.5percent by weight of diethyl-l,2-bis-(3',5'-di-t-butyl4'-hydroxyphenyl)ethanephosphonate. This composition was found to be stablein a Fadeometer for 120 hours. I

When this Example was repeated using 0.1 percent of said stabilizer incombination of 0.5 percent of dilaurylthiodipropionate, the life of thecomposition in the Fadeometer was 240 hours.

EXAMPLE 13 Using the procedure described above, polypropylene wasstabilized with 0.5 percent by weight of diethyl 2,2-bis-(3 ',5

di-t-butyl-4'-hydroxyphenyl)-l-propane phosphonate. The thus stabilizedpolypropylene was found to be stable in the Fadeometer for 360 hours. I

This Example, when repeated using 0.1 percent of said stabilizer and 0.5percent of dilaurylthiodipropionate gave the following results:

537 hrs. 420 hrs.

Oven Aging Test Fadeometer Test Comparable results are obtained when thestabilizers of Examples l2 and 13 are employed in the amount of 0.1percent,

1M0 percent and 5 percent by weight. Similarly, better results areobtained when said stabilizers are used in combination with adistearylthiodipropionate or dilaurylthiodipropionate synergrsts.

Additional examples are presented in Table I below. The samples wereprepared as described above employing the above mentioned polypropylenesubstrate. The oven aging and fadeometer tests were also carried out asdescribed above.

TABLE 1 Exem- Wt., Wt., Oven Fadeple perperaging, ometer, No. Stabilizercent Synergist cent hours hours 14 Compound from 0.1 DSTDP 0.3 880 690Example 3. 15 Compound from 0.1 DSTDP 0.3 670 640 Example 4. l6 Compoundfrom 0.1 DSTDP 0.3 550 590 Example 6. 17 Compound X... 0.1 DSTDP 0.3 780590 18 No stabilizer DSTDP 0.3 25 320No'rE.DSTDP=disteerylthiodlpropionate. Compound X isdimethyl-a,a-bis(4-hydroxy-2-methylphenyl)-n-oeta.decylphosphonate (M.

EXAMPLE l9 Stabilized gasoline is prepared by incorporating intogasoling having no additives and no stabilizers therein 0.05 percent byweight of diphenyl-a,a-bis-(3,5-diisopropyl-4-hydroxyphenyl)nonanephosphonate.

EXAMPLE 20 Paraffin wax (m.p. l25-l 28 F.) is stabilized byincorporating therein 0.001 percent by weight of di-p-t-octylphenyl-2,2-bis-( 3 ,5 '-di-t-butyl-4 -hydroxyphenyl)- l -hexanephosphonate.

EXAMPLE 2] A stabilized high temperature lubricating oil is prepared byincorporating 2 percent by weight of ditriacontyl-S ,5-bis-( 3 ,5'-di-t-butyl-4'-hydroxyphenyl)-n-hexanephosphonate into the lubricant,which comprises diisoamyladipate.

EXAMPLE 22 High impact polystyrene resin containing elastomer (i.e.,butadiene-styrene) is stabilized against loss of elongation propertiesby incorporation of 0.5 percent by weight of dimethyl- 60 ,a-bis-[3,5-di-(l-methylheptadecyl)-nnonadecanelphosphonate.

EXAMPLE 23 A mixture of l kilogram of polyoxymethylene diacetate(molecular weight of about 30,000), 5 g of dimethyl-a,a -bis-(4-hydroxyphenyl)-n-octadecylphosphonate and 2 g of dicyandiamide areextruded at 220 C. to yield a stabilized product.

EXAMPLE 24 A mixture of 1M nylon 6,6 salt (hexamethylene diamineadipate) 0.01 M hexamethylene diamine and 1 percent by weight ofdimethyl-a,a'-bis-(3-methyl-4-hydroxyphenyl)-nocta-decylphosphonate areadded to a polymerization tube and heated for one hour at 220 C. andatmospheric pressure. The temperature is then raised to 285 C. and thepressure reduced slowly to 1 mm. The tube is maintained under theseconditions for 30 minutes, cooled and flushed with nitrogen.

The thus stabilized polyhexamethylene diamine adipate shows less colordevelopment and weight loss than does an unstabilized sample.

What is claimed is:

l. A compound of the formula:

wherein R, R, R and R are alkyl groups having one to 18 carbon atoms orcycloalkyl having five to l2 carbon,

R is hydrogen or alkyl group having up to 18 carbon atoms, R is alkyl,aralkyl or alkaryl having up to carbon atoms,

G is alkylenc group having from one to six carbon atoms.

2. A compound of claim 1 wherein R, R, R and R are lower alkyl groupsortho to the hydroxy groups.

3. A compound of claim 1 wherein R and R are independently lower alkylgroups.

2. A compound of claim 1 wherein R, R1, R2 and R3 are lower alkyl groupsortho to the hydroxy groups.
 3. A compound of claim 1 wherein R4 and R5are independently lower alkyl groups.
 4. A compound according to claim1, said compound beingdiethyl-2,2-bis-(3'',5''-di-t-butyl-4''-hydroxyphenyl)-1-propanephosphonate.
 5. A compound according to claim 1, said compound beingdimethyl 2,2-bis(3'',5''-di-tert-butyl-4''-hydroxyphenyl)-1-nonadecanephosphonate.
 6. Acompound according to claim 1, said compound beingdi-p-t-octylphenyl-2,2-bis-(3'',5''-di-t-butyl-4''-hydroxyphenyl)-1-hexanephosphonate.
 7. A compoundaccording to claim 1, said compound being ditriacontyl-5,5-bis-(3'',5''-di-t-butyl-4''-hydroxyphenyl)-n-hexanephosphonate.